CASE-MIX OF HOME HEALTH PATIENTS UNDER CAPITATED AND FEE-FOR-SERVICE PAYMENT

Objective. We compare case mix of Medicare home health patients under HMO and FFS payment. Study Design. A pseudo-experimental design was em ployed to study case mix using three types of Medicare-certified home health agencies (HHAs): HMO-owned agencies, pure FFS agencies that adm it few Medicare HMO patients (less than 5 percent of admissions are Me dicare HMO patients), and mixed (or contractual) agencies that admit a t least 15 Medicare FFS patients and 15 Medicare HMO patients per mont h. Samples of Providers and Patients. Random samples of Medicare-aged patients (greater than or equal to 65 years) were selected at admissio n between June 1989 and November 1991 from the 38 study HHAs. Sample s izes by agency type were: 308 patients from 9 HMO-owned agencies; 529 patients from 15 pure FFS agencies; and 381 HMO patients and 414 FFS p atients from 14 contractual agencies. Data. Primary longitudinal data were prospectively collected at admission for all patients on health s tatus indicators, demographics, admission source, and home environment . Measures. The most important case-mix measures were functional and p hysiologic indicators of health status, including (instrumental) activ ities of daily living ([I]ADLs). Selected indicators of demographic va riables, prior location, living situation, characteristics of informal caregivers, mental/behavioral factors, and resource needs were also u sed. Principal Findings. (a) The case mix of Medicare FFS patients com pared with Medicare HMO patients was more intense in terms of impairme nts in ADLs, IADLs, and various physiologic conditions. Pressure ulcer s as well as neurological and orthopedic impairments requiring rehabil itation care were also more prevalent among FFS patients. (b) Relative to HMO patients admitted to contractual agencies, HMO patients admitt ed to HMO-owned agencies were moderately more dependent in ADLs and IA DLs. However, only 62 percent of HMO patients admitted to HMO-owned ag encies, in contrast to 77 percent of HMO patients admitted to contract ual agencies, had been hospitalized during the 30 days prior to home h ealth admission. (c) In all, the case mix of patients receiving care f rom HMO-owned agencies is more heterogeneous than the case mix of HMO patients receiving care from contractual agencies.